House Cawdor is one of the six Hive City Houses of Necromunda, making it one of the six original playable factions for the game when it was debuted.
Heavily masked and with a fire motif, House Cawdor has been converted as a whole to the Redemptionist creed of the Imperial Cult. This gives them unique cultural traits, such as always wearing ornate and often hideous masks, and a love of fiery weaponry. It's also made them perhaps the most despised House in Necromunda; even House Delaque is probably more popular than House Cawdor is. Sure, House Delaque is a bunch of backstabbing spies, but at least they're not arrogant killjoys like House Cawdor. The House of Redemption, as it's known, is so suspected of fostering Redemptionist Cult outlaws that bedevil the holdings of the other Houses that it's doubtful that anyone would even care too much if it were confirmed.
In the 8th edition relaunch it is mentioned that their main role in the hive is to scavenge and reclaim any kind of reusable material- the very act of recycling is a miracle in their eyes, and what most people would consider to be worthless garbage they frequently perceive as relics. This is reflected in their new aesthetic of "religious fanatic crossed with dumpster diver". However, their relation with the Imperial House is strained at best, as Lord Cawdor believes himself to be the foremost servant of the Emperor on Necromunda and acknowledges Planetary Governor Helmawr as a peer at best. One of their notable "weapons" is a refurbished autogun mounted on an improvised polearm as a kind of cargo-cult imitation of the Guardian Spears of the Adeptus Custodes, who they have vague legends of being the holiest of the Emperor's servants.
House Cawdor gangs are the fiercest of the House Gangs, being the only gang where every member can learn Ferocity skills - even heavies. They are also the only House Gang (besides House Goliath) where somebody other than a heavy can learn Muscle skills, albeit that honor is restricted to Cawdor gang leaders. In exchange, they have absolutely no capacity for Stealth and the weapons available to them are about as effective as you'd think a bunch of cobbled-together scraps and discarded weaponry would be. They're also one of only two gangs outside of House Escher where somebody other than a gang leader can learn Agility skills.